EP2139019A1 - Procédé pour produire une matrice d'émission de champ avec une netteté de sommet contrôlée - Google Patents

Procédé pour produire une matrice d'émission de champ avec une netteté de sommet contrôlée Download PDF

Info

Publication number
EP2139019A1
EP2139019A1 EP08011691A EP08011691A EP2139019A1 EP 2139019 A1 EP2139019 A1 EP 2139019A1 EP 08011691 A EP08011691 A EP 08011691A EP 08011691 A EP08011691 A EP 08011691A EP 2139019 A1 EP2139019 A1 EP 2139019A1
Authority
EP
European Patent Office
Prior art keywords
substrate wafer
field
holes
emitter
mold
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP08011691A
Other languages
German (de)
English (en)
Inventor
Eugenie Kirk
Soichiro Tsujino
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Scherrer Paul Institut
Original Assignee
Scherrer Paul Institut
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Scherrer Paul Institut filed Critical Scherrer Paul Institut
Priority to EP08011691A priority Critical patent/EP2139019A1/fr
Priority to US13/001,449 priority patent/US8216863B2/en
Priority to PCT/EP2009/056595 priority patent/WO2009156242A1/fr
Priority to EP09769091.1A priority patent/EP2304762B1/fr
Priority to JP2011515276A priority patent/JP2011525689A/ja
Publication of EP2139019A1 publication Critical patent/EP2139019A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
    • H01J9/025—Manufacture of electrodes or electrode systems of cold cathodes of field emission cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/30—Cold cathodes, e.g. field-emissive cathode
    • H01J1/304—Field-emissive cathodes
    • H01J1/3042—Field-emissive cathodes microengineered, e.g. Spindt-type
    • H01J1/3044—Point emitters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00—Electrodes common to discharge tubes
    • H01J2201/30—Cold cathodes
    • H01J2201/304—Field emission cathodes
    • H01J2201/30403—Field emission cathodes characterised by the emitter shape
    • H01J2201/30407—Microengineered point emitters
    • H01J2201/30411—Microengineered point emitters conical shaped, e.g. Spindt type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2209/00—Apparatus and processes for manufacture of discharge tubes
    • H01J2209/02—Manufacture of cathodes
    • H01J2209/022—Cold cathodes
    • H01J2209/0223—Field emission cathodes

Definitions

  • the present invention relates to a method for producing a field-emitter structure having controlled apex sharpness.
  • a method to precisely control the shape of the mold holes is described for the purpose of producing field-emitter arrays with uniform apex sharpness and blunted side ridges.
  • the field-emitter arrays are produced by the deposition of the electron emitter material onto the mold substrates and subsequent removal of the mold substrates.
  • the sharpness of the emitter apex and the side ridges of the emitters are controlled by precisely shaping the mold holes by the crystal orientation dependent etching of single-crystal substrates in combination with the topography-dependence of the oxidation rate.
  • This invention relates to new methods of controlling the shape of the mold used for manufacturing high-current emitting field-emitter array structures.
  • the importance of the optimal apex curvature for the high current can be illustrated by a following numerical example: as reported by Dyke and Trolan ( W. P. Dyke and J. K. Trolan, Field emission: large current densities, space charge, and the vacuum arc, Phys. Rev. 89, 799-808 (1953 )), the stable field-emission current is obtained when the current density is kept at most around ⁇ 10 7 A/cm 2 with the corresponding emitter apex field in the order of 50-100 MV/cm. Accordingly, when the apex curvature is 1 nm, the total emission current per emitter is at most ⁇ 300 nA.
  • Zimmerman U.S. Pat. 5,141,459 ) disclosed a method to fabricate a field-emitter structure with non-sharp tip apex curvature by incompletely filling the mold holes with the sacrificial material.
  • this method achieving uniform apex curvature is not an easy task.
  • Marcus et al. U.S. Pat. 5,201,992
  • the uniformity of the flat-topped emitter apex is an issue here.
  • Yagi et al. (U.S. Pat. 6,227,519 B1 ) disclosed a method to control the tip-shape based on the molding method by applying a heat flowable material in the mold holes.
  • the object of the present invention is achieved by modifying the shape of the mold produced using a single-crystal semiconductor wafer by lithography and crystal-orientation dependent etching, whilst maintaining the thickness of a passivation layer on the mold to protect the electron emitting material during the substrate removal process.
  • the field emission cathode structure is formed in the thus modified mold by coating the inside with electron emitting material, followed by removal of the mold substrate.
  • the method provides a way of manufacturing a field-emitter ' structure with controlled shape with apex diameter between 1 and 100 nm; comprising the steps of:
  • Figures 1 to 3 depict several of the basic preliminary steps in manufacturing substrate wafers to be used to manufacture a field emitter array structure with controlled shape in accordance with the invention, up to the stage described by Gray et al (Henry F. Gray, Richard F. Greene, Method of manufacturing a field-emission cathode structure , U.S. Pat. No. 4,307,507 issued Dec. 29, 1981 ) comprising a sharpened tip and side ridges.
  • Figure 4 depicts the top plan view of the mold resulting from the processing steps described with relation to Figures 1 to 3 .
  • Figures 5 and 6 depict the final steps to manufacture a field-emitter array structure with controlled shape.
  • Figure 7 depicts the top plan view of the mold resulting from the processing steps depicted in Figure 6 .
  • Figure 8 shows a scanning electron microscopy image of a molybdenum field emitter structure manufactured by using a single-oxidation mold where the present invention was not applied.
  • Figure 9 shows a scanning electron microscopy image of a molybdenum field emitter structure manufactured by using a mold where the shape of the holes is modified in accordance with the present invention.
  • Figure 10 shows an enlarged view of the scanning electron microscopy image of the emitter apex of a molybdenum field emitter structure manufactured by using a mold where the shape of the holes are modified in accordance with the present invention.
  • the starting point of the invented process is a wafer substrate 101 (see Fig. 1 for cross-sectional and Fig. 2 for plan view) where pyramidal shaped holes 110 having four facets with the [111] crystal orientation are etched in the single-crystal semiconductor wafer with [001] crystal orientation.
  • the holes 110 are 1 to 3 ⁇ m 2 in size and the precise shape of the holes 110 is determined by the anisotropy of the crystal-orientation dependent etching rate to secure the uniformity of the holes 110.
  • the apex curvature of individual emitters is typically in the range of 100 nm.
  • a thermal oxidation process is applied to the wafer substrate 101, which forms a superficial oxide layer 103 (see Figure 3 for cross-sectional and Figure 4 for plan view).
  • the thickness of the oxide layer 103 is chosen to be equal to 400-500 nm. Oxide growth is slower at the tips and ridges in the holes 110 of the wafer structure 101 (mold) where less oxygen is available. Consequently, the surface of the oxide becomes cusp-shaped at these junctions. On the other hand, the sharpness of the junctions is blunted at the interface between the oxide film 103 and a so-modified wafer substrate 102.
  • the apex curvature of individual emitters is typically in the range of 1 nm (see Figure 8 ).
  • the oxide film 103 is selectively removed and the mold wafer 104 having smooth, concave junctions at the bottom of the modified holes 112 and at the side ridges is formed (see Fig. 5 for cross-sectional view).
  • the oxide removal can be effectively achieved by wet etching using hydrofluoric acid for silicon wafers or GaAs wafers.
  • the curvature of the bottom of the modified holes 112 typically has a radius greater than several hundred nm.
  • thermal oxidation is again applied to the so-modified wafer 104, which forms another oxide layer 106 on top of the resulting wafer 105 (see Figure 6 for cross-sectional and Figure 7 for plan view).
  • the oxide layer 106 also protects the electron emitter material to be deposited on top of it during the process to remove the resulting wafer substrate 105. Therefore, the thickness of the oxide layer 106 is set to be sufficiently thick in the range of 300-600 nm. In a preferred embodiment, the thickness of the oxide layer 106 is chosen to be 400 nm. As the result of topography dependent oxidation rate on the surface of the holes 112, the surface of the oxide film 106 is rounded at the junctions between the side facets and at the bottom of the holes 113.
  • the field-emitter array cathode is subsequently obtained by coating the mold with electron emitting layer, which is extended to sufficient thickness to sustain the resultant field-emitter array, and then by removing the resulting wafer substrate 105 and the oxide film 106 by chemical etching.
  • the apex diameter of individual emitters is now typically in the range of 40 nm (see Figures 9 and 10 ) with the apex size uniformity in the range of 15%.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Cold Cathode And The Manufacture (AREA)
EP08011691A 2008-06-27 2008-06-27 Procédé pour produire une matrice d'émission de champ avec une netteté de sommet contrôlée Withdrawn EP2139019A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
EP08011691A EP2139019A1 (fr) 2008-06-27 2008-06-27 Procédé pour produire une matrice d'émission de champ avec une netteté de sommet contrôlée
US13/001,449 US8216863B2 (en) 2008-06-27 2009-05-29 Method for producing a field-emitter array with controlled apex sharpness
PCT/EP2009/056595 WO2009156242A1 (fr) 2008-06-27 2009-05-29 Procédé de production d’un réseau d’émetteurs de champ à netteté de sommet contrôlée
EP09769091.1A EP2304762B1 (fr) 2008-06-27 2009-05-29 Procédé de production d'un réseau d'émetteurs de champ à netteté de sommet contrôlée
JP2011515276A JP2011525689A (ja) 2008-06-27 2009-05-29 先端の尖鋭度が制御される電界放出エミッタアレイの製造方法

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP08011691A EP2139019A1 (fr) 2008-06-27 2008-06-27 Procédé pour produire une matrice d'émission de champ avec une netteté de sommet contrôlée

Publications (1)

Publication Number Publication Date
EP2139019A1 true EP2139019A1 (fr) 2009-12-30

Family

ID=39938453

Family Applications (2)

Application Number Title Priority Date Filing Date
EP08011691A Withdrawn EP2139019A1 (fr) 2008-06-27 2008-06-27 Procédé pour produire une matrice d'émission de champ avec une netteté de sommet contrôlée
EP09769091.1A Not-in-force EP2304762B1 (fr) 2008-06-27 2009-05-29 Procédé de production d'un réseau d'émetteurs de champ à netteté de sommet contrôlée

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP09769091.1A Not-in-force EP2304762B1 (fr) 2008-06-27 2009-05-29 Procédé de production d'un réseau d'émetteurs de champ à netteté de sommet contrôlée

Country Status (4)

Country Link
US (1) US8216863B2 (fr)
EP (2) EP2139019A1 (fr)
JP (1) JP2011525689A (fr)
WO (1) WO2009156242A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013004514A1 (fr) 2011-07-01 2013-01-10 Paul Scherrer Institut Structure de cathode à émission de champ et procédé de commande de celle-ci

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4307507A (en) 1980-09-10 1981-12-29 The United States Of America As Represented By The Secretary Of The Navy Method of manufacturing a field-emission cathode structure
US4604304A (en) * 1985-07-03 1986-08-05 Rca Corporation Process of producing thick layers of silicon dioxide
US4964946A (en) 1990-02-02 1990-10-23 The United States Of America As Represented By The Secretary Of The Navy Process for fabricating self-aligned field emitter arrays
US5141459A (en) 1990-07-18 1992-08-25 International Business Machines Corporation Structures and processes for fabricating field emission cathodes
US5201992A (en) 1990-07-12 1993-04-13 Bell Communications Research, Inc. Method for making tapered microminiature silicon structures
US5580827A (en) * 1989-10-10 1996-12-03 The Board Of Trustees Of The Leland Stanford Junior University Casting sharpened microminiature tips
US5827752A (en) 1995-10-24 1998-10-27 Korea Institute Of Science And Technology Micro-tip for emitting electric field and method for fabricating the same
US6227519B1 (en) 1997-05-07 2001-05-08 Canon Kabushiki Kaisha Female mold substrate having a heat flowable layer, method to make the same, and method to make a microprobe tip using the female substrate
DE10236149A1 (de) * 2002-08-05 2004-02-26 Universität Kassel Verfahren zur Herstellung einer eine schmale Schneide oder Spitze aufweisenden Struktur und mit einer solchen Struktur versehener Biegebalken
US20060084192A1 (en) * 1998-10-06 2006-04-20 Tianhong Zhang Process for forming sharp silicon structures

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0887958A (ja) * 1994-09-16 1996-04-02 Toshiba Corp 電界放出型冷陰極装置及びその製造方法
JPH08166391A (ja) * 1994-12-13 1996-06-25 Nikon Corp 走査型プローブ顕微鏡用プローブ及びその製造方法
JPH0972926A (ja) * 1995-09-05 1997-03-18 Nikon Corp カンチレバー及びその製造方法、並びに前記カンチレバーを用いた走査型プローブ顕微鏡
JP3079993B2 (ja) * 1996-03-27 2000-08-21 日本電気株式会社 真空マイクロデバイスおよびその製造方法
WO1998044529A1 (fr) * 1996-06-25 1998-10-08 Vanderbilt University Structures, reseaux et dispositifs a emission de champ sous vide a micro-pointe et techniques de fabrication
JPH10208624A (ja) * 1997-01-24 1998-08-07 Canon Inc 電界放出型電子放出素子の製造方法およびこれを用いた画像形成装置

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4307507A (en) 1980-09-10 1981-12-29 The United States Of America As Represented By The Secretary Of The Navy Method of manufacturing a field-emission cathode structure
US4604304A (en) * 1985-07-03 1986-08-05 Rca Corporation Process of producing thick layers of silicon dioxide
US5580827A (en) * 1989-10-10 1996-12-03 The Board Of Trustees Of The Leland Stanford Junior University Casting sharpened microminiature tips
US4964946A (en) 1990-02-02 1990-10-23 The United States Of America As Represented By The Secretary Of The Navy Process for fabricating self-aligned field emitter arrays
US5201992A (en) 1990-07-12 1993-04-13 Bell Communications Research, Inc. Method for making tapered microminiature silicon structures
US5141459A (en) 1990-07-18 1992-08-25 International Business Machines Corporation Structures and processes for fabricating field emission cathodes
US5827752A (en) 1995-10-24 1998-10-27 Korea Institute Of Science And Technology Micro-tip for emitting electric field and method for fabricating the same
US6227519B1 (en) 1997-05-07 2001-05-08 Canon Kabushiki Kaisha Female mold substrate having a heat flowable layer, method to make the same, and method to make a microprobe tip using the female substrate
US20060084192A1 (en) * 1998-10-06 2006-04-20 Tianhong Zhang Process for forming sharp silicon structures
DE10236149A1 (de) * 2002-08-05 2004-02-26 Universität Kassel Verfahren zur Herstellung einer eine schmale Schneide oder Spitze aufweisenden Struktur und mit einer solchen Struktur versehener Biegebalken

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
H. UMIMOTO; S. ODANAKA; I. NAKAO: "Numerical Simulation of Stress-Dependent Oxide Growth at Convex and Concave Corners of Trench Structures", IEEE ELECTRON DEVICE LETTERS, vol. 10, no. 7, July 1989 (1989-07-01), pages 330
M. DEHLER; A. E. CANDEL; E. GJONAJ: "Full scale simulation of a field-emitter arrays based electron source for free electron lasers", J. VAC. SCI. TECHNOL, vol. B24, no. 2, 2006, pages 89 - 2
M. DEHLER; A. E. CANDEL; E. GJONAJ: "Full scale simulation of a field-emitter arrays based electron source for free electron lasers", J. VAC. SCI. TECHNOL., vol. B24, no. 2, 2006, pages 892 - 897
M. SOKOLICH ET AL.: "Field emission from submicron emitter arrays", INTERNATIONAL ELECTRON DEVICE MEETING, 1990
W. P. DYKE; J. K. TROLAN: "Field emission: large current densities, space charge, and the vacuum arc", PHYS. REV., vol. 89, 1953, pages 799 - 808

Also Published As

Publication number Publication date
US8216863B2 (en) 2012-07-10
WO2009156242A1 (fr) 2009-12-30
EP2304762A1 (fr) 2011-04-06
US20110104832A1 (en) 2011-05-05
JP2011525689A (ja) 2011-09-22
EP2304762B1 (fr) 2013-09-18

Similar Documents

Publication Publication Date Title
US6780075B2 (en) Method of fabricating nano-tube, method of manufacturing field-emission type cold cathode, and method of manufacturing display device
JP3793219B2 (ja) パッキング密度の高い電子放出デバイスの製造方法
US5562516A (en) Field-emitter fabrication using charged-particle tracks
EP0508737B1 (fr) Procédé de fabrication d'une cathode froide métallique de dimensions microscopiques
US5702281A (en) Fabrication of two-part emitter for gated field emission device
WO1991003066A1 (fr) Procede a auto-alignement de porte pour la fabrication de reseaux d'emetteurs de champs
JP2001236879A (ja) カーボンナノチューブを用いた３極電界放出素子の製造方法
US20090325452A1 (en) Cathode substrate having cathode electrode layer, insulator layer, and gate electrode layer formed thereon
KR100243990B1 (ko) 전계방출 캐소드와 그 제조방법
JP5082186B2 (ja) 炭素系材料突起の形成方法及び炭素系材料突起
US5993281A (en) Sharpening of field emitter tips using high-energy ions
US6057172A (en) Field-emission cathode and method of producing the same
EP2304762B1 (fr) Procédé de production d'un réseau d'émetteurs de champ à netteté de sommet contrôlée
JP3033179B2 (ja) 電界放出型エミッタ及びその製造方法
US5607335A (en) Fabrication of electron-emitting structures using charged-particle tracks and removal of emitter material
US20050255613A1 (en) Manufacturing of field emission display device using carbon nanotubes
JPH09270228A (ja) 電界放射型電子源の製造方法
Huq et al. Fabrication of sub‐10 nm silicon tips: A new approach
US20070200478A1 (en) Field Emission Device
RU2832232C1 (ru) Способ изготовления острийно-лезвийного автоэмиссионного катода
Lee et al. New approach to manufacturing field emitter arrays with sub‐half‐micron gate apertures
JPH05242797A (ja) 電子放出素子の製造方法
JP2737675B2 (ja) 縦型微小冷陰極の製造方法
JPH05242796A (ja) 電子放出素子の製造方法
KR100290136B1 (ko) 전계방출소자제조방법

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA MK RS

AKY No designation fees paid
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20100701

REG Reference to a national code

Ref country code: DE

Ref legal event code: 8566